Reflective display device



P 1960 J. H. LEMELSON 2,951,419

REFLECTIVE DISPLAY DEVICE Original Filed June 11; 1953 Fig. 5

INVENTO Jerome H.Lemel BY $224 c. PW

REFLECTIVE DISPLAY DEVICE Jerome H. Lemelson, 239 High St., Perth Amboy,NJ. Original application June 11, 1953, Ser. No. 360,954. Divided andthis application Oct. 15, 1956, Ser. No. 616,089

8 Claims. (CI. 88-82) The present invention relates to reflectingdevices, and in particular is concerned with display devices of thereflex-reflector type which appear, to an observer moving with a lightsource, to flash on and off, scintillate or change optical composition.This is a division of my copending application Serial No. 360,954, filedJune 11, 1953, and entitled Display Devices.

Reflex-reflecting devices are generally known in the art and have thecharacteristic of returning light to an observer or an observation pointat or near the source of light which is directed toward the reflectingdevice. A typical reflex-reflector embodies a sheet having manythousands of minute optical lenses, usually in the form of spheresapplied in front of a highly reflective surface. Light rays striking thereflex-reflector over a wide range of incident angles are focused by thespheres to a point in front of the highly reflective surface in back ofthe optical system, and then are returned through the spheres back tothe moving source. Such reflex-reflector may be constructed to providethe necessary reflection over narrow or wide angles, depending upon .theconstruction of the reflector. Included among the numerous patents andpublications which disclose constructional details of typicalreflex-reflectors are U.S. Patents Nos. 2,294,930, 2,326,634 and2,592,882.

The characteristics of reflex-reflectors are such as to make thememinently suitable for use on highway signs,

, street signs, safety markers, advertising media, truck backs and thelike. At night, the reflex characteristics are such that it will appearto an observer moving with a vehicle having its headlights beamed on thereflexreflector that the reflex-reflector contains a light source. Thisoptical phenomena continues until the vehicle has virtually passed thereflex-reflector and has its headlights beamed at approximately an angleof 90 with respect to the reflector.

It is broadly an object of the present invention to provide improveddisplay devices of the reflex-reflector type making possible new andpronounced visual effects- Despite the improved performance ofreflex-reflectors in various warning, advertising and display devices,particularly when compared to conventional reflectors or morecomplicated internally illuminated devices, there exists the need toattain varied and different effects with devices operating on thereflex-reflector principle. Experience indicates that warning anddisplay devices which are intermittently illuminated have a morepronounced effect and in general are more eye catching. Familiar to allmotorists are blinker lights, theblinker road markers, and blinker'cu'rve devices warning which immediately attract the attention.

It is a further object of the present invention to provide displaydevices of the reflex type which intermittently exhibit changes inoptical composition as the light source and'the observer move relativeto the device. Specifically, it is within the contemplation of thepresent invention to provide new and improved reflecting display devicesor present indications of different colors.

In accordance with an illustrative embodiment demonstrating features ofthe present invention, a reflecting device is provided for use with amoving source of light which includes a transparent body having a lensthereon or associated therewith which is adapted to converge light fromthe moving source into a number of discrete light beams.Reflex-reflecting means are associated with the transparent body andcooperate with the lens means, the reflex-reflecting means includingplural reflex-reflecting surfaces which return the discrete light beamsto an observation point adjacent the moving source, and further plu-r-alregions of different light reflectivity. The regions of different lightreflectivity may be regions of total or partial light absorption,regions which are arranged to reflect light to regions other thanthose'successively occupied by the moving observation point, and regionsof different color-emitting properties. Advantageously, many variedeffects may be obtained by structures which are simple and completelycompatible with existing techniques for the manufacture ofreflex-reflecting devices.

The above brief description, as well as further objects, features andadvantages of the present invention will be best appreciated byreference to the following detailed description of a preferredembodiment, when taken in conjunction with the accompanying drawings,wherein:

Fig. l is a sectional view of a first embodiment of the presentinvention capable of producing an on-off dis- Fig. 2 is a sectional viewof a second embodiment of the present invention likewise capable ofproducing an on-off display;

Fig. 3 is a sectional view of a third embodiment of the presentinvention which is arranged to produce a flickering or flashing display;

Fig. 4 is a sectional view of a fourth embodiment of the presentinvention which is arranged to provide a flashing interrupted reflectionand demonstrating further features of the invention; and

Fig. 5 is a sectional view of a fifth embodiment of the invention whichis arranged to produce changing composition and color in accordance withfurther aspects of the present invention.

Referring now specifically to the drawings, there is shown in Fig. 1 adisplay device, which has generally been designated by the referencenumeral 10. The device 143 embodies a transparent panel 12 which isadapted to receive light from a moving source (i.e., a vehicle with thehead lamps beamed on the sheet or panel 12). The front and rear surfaces12a, 12b of the transparent sheet or panel 10 are formed with integralconvex lens-like formations, generally designated by the referencenumerals 14, 16 which comprise semi-spherical or semi-cylindrical ribsintegral with the light transmitting panel, which may be fabricated fromglass or plastic. The rear surface 12]) of the panel 12 is coated with areflecting layer 18 which is arranged to redirect the light raysimpinging thereon back through the front surface 12a of the panel 12 andthrough the media to the external moving light source. The reflectivelayer or coating 18 may include a thin vacuum deposit of aluminummetallized onto the panel in accordance with well known vaportechniques. If desired, a protective coating (not shown) of plastic orother similar material may be applied over the reflective layer 18 toprevent the same from. being rubbed off, marred, or otherwise affected.The relative sizes, shapes and spacing of the projections or lenticularformations 14, 16 on opposite surfaces of the panel 11 will determinethe visual efl'ect to the observer at the moving source of light. Therelative sizes of the projections or lens formations 14, 16 is arbitraryand will be determined by spacings to give a flickering or rollingreflection to a light beam entering the front surface 12a.Manyvariations will occur to those skilled in the art when Working witha panel constructed in accordance with the showing of Fig. l.

In Fig. 2 there is shown in section a further form of the presentinvention which includes a transparent panel or sheet 20 havingrelatively large and essentially semi cylindrical or semi-sphericalformations 22 on the front face 20a thereof. On the rear face 201') ofthe panel or sheet, there is provided smaller similarly-shapedformations or projections 24 which are disposed in a spaced apartseries. The formations24 will be either semicylindrical orsemi-spherical depending upon the configuration of the formations 22.The series of projections 24 on the rear surface 'are separated by flatsurfaces, one of which has been designated by the reference numeral 26.The entire rear surface Ztlb is covered with a reflective coating, whichhas been generally designated by the reference character 28, Whichcoating may be applied in the manner previously described.

When light enters the transparent sheet 20 through the front surface 20athereof at any given angle, the respective lens-like formations orlenticules 22 on the front face converge into a number of discrete bandsand focus each band or bundle of light rays within the transparent sheetat the focal point or focal line of the lens like formation. The lightthen diverges until it strikes the reflective rear surface 20b of thepanel on which surface there are spaced regions 24 which are adapted toreflect and refocus the discrete light bundle or hands and return saidlight bundles or hands to an observation point or an observer adjacentthe source of light. As the angle of incidence of the beam changes(i.e., in response to movement of the source), the light is focused bythe lens-like formations 22 onto the flat bands 26 which are ofdifferent light reflectivity and do not direct the light back to themoving source. In the illustrative embodiment, the bands 26 are of adifferent radius of curvature and accordingly will either partly absorbor totally absorb light incidence thereon and preclude return of thelight to the source. Thus the unusual optical phenomena described hereinis obtained. By varying the spacing and dimensioning of the regions ofdifferent light reflectivity, and/ or of the component parts of thereflex-reflector, varying effects may be obtained.

In Fig. 3 there is shown in section a still further embodiment of thepresent invention which embodies two sheets or panels, respectivelydesignated by the reference numerals 30, 32. The panels or sheets 39, 32are assembled in confronting relation as will hereinafter be described.The panel or sheet 30 is of transparent plastic glass or the like andhas its front face 30a formed with a number of lens-like formations orprojections 34which are effective to converge the light entering thepanel into a number of discrete bands, as previously described. On therear surface 30b of the light-transmitting panel 30, there are provideda number of regions 36 each having an irregular or translucent surfacewhich absorb or scatter light projected thereon by the lens-likeformations 34. Light absorption or scattering at the region 36 may beattained in any one of many ways including the formation of indentationor irregularities on the rear surface 301). Further, it is within thecontemplation of the invention to change the light reflecting propertiesof the regions 36 of the rear surface by rendering such regions opaqueso that the light striking such regions is totally or partiallyabsorbed. The rear panel 32 is a reflex-reflector, such as thecommercially available reflect-reflecting sheeting sold under thetrademark Scotchlite, which is a product of Minnesota Mining andManufacturing Co. of St. Paul, Minnesota. Such a reflex-reflector isavailable in the form of sheets of a flexible resin backing havingimbedded therein a multiplicity of glass spheres which operate as minuteoptical lenses to return light to its source from a highly reflectivesurface on the back of the sheeting. Other forms of commerciallyavailable reflex-reflectors are contemplated for use as the element 32of the illustrative assembly in Fig. 3.

The operation of the device in Fig. 3 is similar to that described inconjunction with Figs. 1 and 2. If the lens-like projections orformations 34 are cylindrically shaped, the light will be focused aslines or bands at or near the interface between the confronting faces ofsheets 36, 32. The reflex reflective surface provided by the sheeting 32will reflect the light back through the transparent panel 39 along theincident path to the source of light. Prescribed regions of the returnlight will be totally or partially absorbed or scattered in that theyare subjected to the regions 36 of different light reflectivity. As theangle of incident light changes, the position of the light bands at theinterface 38 shifts and eventually will fall onto the regions ofdifferent reflectivity from that of the reflex-reflector 32 resulting inthe changed optical elfect achieved by the present invention.

The embodiment of Fig. 4 includes a transparent sheet 39 similar to thesheet 30 of Fig. 3 and a reflex-reflector 32 similar to thereflex-reflector 32 illustrated in Fig. 3. However the regions ofdifferent light reflectivity in this embodiment are obtained bylight-absorbing bands or grids 449 which are printed or otherwiseapplied to either of the confronting surfaces at the interface 38. Ifthe light-absorbing bands 4% are equi-spaced and essentially equal inwidth to the light bands provided at the interface by the front panel 3%a definite chopping of the reflected light is obtained as the angle ofthe incident beam changes relative to the assembly.

In Fig. 5 there is shown a still further variation of the generalarrangement illustrated in Figs. 3 and 4. As before a transparent sheet30 is provided in assembly with a reflex-reflector 3 2", the sheetsmeeting at an interface 38". At the interface 38" there is provided twogroups of adjacent bands or strips, the bands of one group beingdesignated by the reference numeral 42, and the bands of the other groupbeing designated by the reference numeral 4-4. The bands of therespective groups are interdigitated and are of different color or lightreflectivity. Most conveniently, the bands are formed by printing on therear surface of the sheet 30 which is essentially flat. As the discretebands of light from the sheet 30" move with changing incident angles oflight from the moving source, the bands of light shift from one group(i.e. 42) to the other group (i.e. 44) and thus the observer at oneinstant in time will see a pattern of one color and then a pattern ofanother color. By the principles demonstrated in accordance with Fig. 5still further and diiferent visual effects may be readily obtained.

A latitude of modification substitution and change is intended in theforegoing disclosure and it will be appreciated that features andconcepts derived from the several figures may be employed in varyingcombinations to obtain many different visual effects. In the appendedclaims the term different light reflectivity is intended to includetotal or partial light absorption, scattering of light at an angle otherthan that which would direct the light back to the point of observationor the light source, and regions or areas of different color. In someinstances some features of the invention will be used without acorresponding use of other features. It is intended that the appendedclaims be construed broadly and in a manner consistent with the spiritand scope of the disclosure herein.

1. An improved multipatterned reflecting device which is characterizedby its ability to cause a reflected light beam to systematically vary inappearance as a light source is moved across the field of the device,which comprises in combination:

(a) a transparent and relatively thin sheet of material having a frontface composed of a plurality of parallel cylindrically shaped lenseswhich are adapted to focus incident light into a plurality of discretelight beams,

(b) a pattern disposed behind the rear face of said transparent sheet,said pattern consisting of a plurality of parallel bands including afirst array of spaced bands of material no greater than the diameter ofsaid parallel cylindrically shaped lenses and being repetitive inarrangement, said bands of material being interposed between a secondarray of spaced band areas having dissimilar light transmittingproperties than the light transmitting properties of the material ofsaid first array of bands,

a reflex-reflector means containing a plurality of reflex-reflectingsurfaces positioned with its front face directly behind said pattern,and

(d) said pattern serving to divide incident light beams into a pluralityof discrete reflected parallel beams of varying reflected intensities,the comparative intensities being augmented in contrast by saidreflex-reflector means.

2. The reflecting device of claim 1 wherein said pattern consists of atleast one layer of light absorbing material disposed in the form of apattern between and adjacent to the rear face of said transparent sheetand the front face of said reflex-reflector means.

3. The reflecting device of claim 2 wherein said pattern comprisesspaced-apart opaque strips of light absorbing material.

4. The reflecting device of claim 2 wherein said contrasting lightabsorbing areas are of different colors.

5. The reflecting device of claim 1 wherein said pattern comprises alayer of material having contrasting translucent light absorbing areas.

6. The reflecting device of claim 1 wherein said pattern comprisescontrasting light absorbing areas, said areas being disposed inspaced-apart elongated strips, the direction of elongation beingparallel to the axes of the cylindrically shaped lenses of saidtransparent face.

7. The reflecting device of claim 1 wherein said pattern comprises alight controlling layer consisting of spaced-apart light absorbing areasof contrasting colors.

8. The improved reflecting device of claim 1 wherein said lenses aresubstantially semi-cylindrical and join each other at substantiallydiametric points to thus form a corrugated surface, and said patternforming means comprising a layer having contrasting light absorbingareas disposed in elongated strips, the direction of elongation beingparallel to the axes of the corrugations of said transparent face.

References Cited in the file of this patent UNITED STATES PATENTS1,150,374 Kanolt Aug. 17, 1915 1,989,553 Kanolt Jan. 29, 1935 1,992,608Deninson Feb. 26, 1935 2,054,289 Jackson Sept. 15, 1936 2,121,132 RyderJune 21, 1938 2,121,566 Leray June 21, 1938 2,149,171 Grote Feb. 28,1939 2,319,742 Luce May 18, 1943 2,351,034 Gabor June 13, 1944 2,379,702Gebhard July 3, 1945 2,432,896 Hotchner Dec. 16, 1947 FOREIGN PATENTS54,371 Denmark Feb. 21, 1938

